1. Field of the Invention
The present invention is directed to an improved blood specimen collection system for collecting blood from humans and domestic animals. More particularly, the present invention is directed to a blood specimen collector cylinder which includes a protective sheath for covering the needle used during the collection, whereby the used needle can be covered by the protective sheath and discarded without being touched by human hands.
2. Brief Description of the Prior Art
Blood specimen collectors have been known in the art for a long time. More particularly, hypodermic syringes and needles have been used in the art for a long time to draw blood samples from humans and domestic animals. Current hospital and clinical practice, however, requires the taking of blood specimens to occur rapidly and with inexpensive and readily disposable equipment with safety. Ordinary hypodermic syringe and needle combinations do not meet these requirements well. The below-described state-of-the-art blood collecting system, on the other hand, permits rapid and safe collection of blood specimen and uses a disposable blood collector and a collection tube in which the collected blood specimen is initially received and in which it may be stored until desired blood tests are performed. More particularly, and still with reference to the state-of-the-art blood collecting system, for the drawing of blood specimen, a standard disposable needle assembly is placed into a threaded hole in the end wall of a hollow cylinder.
The standard disposable needle assembly includes an externally extending hollow needle which is used to xe2x80x9cstickxe2x80x9d the patient to draw blood, and another needle extending inwardly into the interior of the hollow cylinder. The two needles are coaxial and are in fluid communication with one another. The collection tube is sealed at one end with a pierceable rubber or like septum. The collection tube is placed within the interior of the cylinder so that the septum is pierced by the inwardly extending needle. The patient""s blood is then drawn into the collection tube through the needles without coming into contact with the hollow cylinder. After the collection tube is withdrawn from the cylinder, the blood collection assembly is discarded. For safety reasons this requires placement of a protective cap or sheath on the externally extending needle to avoid accidental needle stick. Although the above-summarized prior art blood specimen collecting apparatus works well, it has a Serious disadvantage in that it is necessary to manipulate and touch the needle assembly after the needle has been in contact with the patient""s blood. Such manipulation unfortunately gives rise to the possibility of accidental wounding or pricking of a health care worker by the needle which has been used to collect blood capable of transmitting infectious diseases. It is well known in the art that certain serious, even fatal, diseases, such as hepatitis and AIDS, may be spread in this manner, that is, through accidental contact with infected blood. In light of the foregoing, there is a definite need in the art for a blood sample collecting system or apparatus in which exposure to contaminated needles is minimized or eliminated. This need has not been met in the prior art, although various devices have been made in the hypodermic syringe and related arts for drawing blood specimens and for performing and facilitating the process of injection of drugs with hypodermic syringes. U.S. Pat. No. 3,706,306 describes a blood specimen collecting apparatus substantially of the type which is referred to in the foregoing brief description as xe2x80x9cstate-of-the-artxe2x80x9d. U.S. Pat. No. 2,393,196 describes a hypodermic syringe apparatus having a pivotable end piece to which a needle can be mounted. U.S. Pat. Nos. 4,653,511; 4,710,170; 4,123,091; 2,376,436; 4,641,663; French Patent No. 334,207; German Offenlegungsschrift Pat. No. 2451398 and German Offenlegungsschrift Pat. No. 2815377 describe still further blood specimen collector and syringe type devices which comprise the background of the present invention.
It is an object of the present invention to provide a blood specimen collecting system in which a used needle assembly can be discarded without being touched by human hands, thereby minimizing the health care worker""s exposure to contaminated needles which may potentially spread dangerous or fatal diseases. It is another object of the present invention to provide a blood specimen collecting system which meets the above-noted objective and which utilizes standard needle assemblies and blood sample collection tubes. The foregoing and other objects and advantages are attained by a blood collecting system which utilizes standard blood collecting tubes having one of their ends sealed by a pierceable septum. A standard disposable needle assembly used in conjunction with the system includes coaxial first and second hollow needles in fluid communication with one another and an intermediate portion of enlarged diameter which is dimensioned to fit within an aperture provided in an end wall of a hollow cylinder. When the needle assembly is mounted into the cylinder, the first needle is axially extended and available to prick a patient to draw blood. The second needle is extended inwardly to pierce the septum of the standard blood collecting tube which is placed within the interior of the cylinder.
A protective sheath with two clips is concentrically mounted to the barrel cylinder with slot on both sides of the barrel so that the hollow cylinder can move down to cover the patent contacted needle. On both side of the barrel, there are one upper slot and one lower slot, a slot channel between the upper slot and lower slot. The clip is shaped so that it can be snap in the upper and lower slot, and can be only slide down from the upper slot to lower slot, but not backwards. After the needle is taken out from a patient, the clip will be pushed down out of the upper slot, then slide down through the slot channel, then be pushed down to snap in the low slot of the barrel in order to cover the used needle from a patient. When the clip is snapped in the lower slot, it is permanent locked in. The apparatus of the invention eliminates the health care worker""s exposure to accidental needle pricks. The features of the present invention can be best understood, together with further objects and advantages, by reference to the following description, taken in connection with the accompanying drawings.